Pipe wrench having rack and slidable catch jaw adjustment means



Dec. 12, 1967 c. E. POOLER, JR

PIPE WRENCH HAVING RACK AND SLIDABLE CATCH JAW ADJUSTMENT MEANS Filed Aug. 4, 1966 2 Sheets-Sheet umi smm

INVENTOR. C rroll E. Pooler,Jr. BY

ma i! A! ATTORNEYS Dec. 12, 1967 c. E. POOLER, JR 3,357,285

PIPE WRENCH HAVING BACK AND SLIDABLE CATCH JAW ADJUSTMENT MEANS Filed Aug. 4, 1966 2 Sheets-Sheet B l O I /3 ld I40 i F I G o 3 u [40. l4 3 4b P Fl 6. 4 l3 ac- 40 lb 3a "1 l3 4c I40 i F as .e. 7 W W '0 fil "7" 4 W /M lb 3 6b In INVENTOR. 6b Carroll E.Pooler,Jr.

BY FIG. 8. W

ATTORNEYS United States Patent P ABSTRACT OF THE DISCLGSURE The pipe wrench has a tubular base of rectangular crosssection having slots in its upper and lower walls intermediate its ends; a fixed jaw head at the front end of the base having a lateral extension carrying a fixed jaw; the tube having a rectangular block in its rear end provided with an axial bore receiving a plunger slidable therein, the plunger having a second head on its inner end slidable in said tube with a coiled spring around said plunger for normally projecting said second head forwardly of the tube; the second head carrying a movable jaw base having a reduced neck slidable in the lower slot in the tube, with the movable jaw eccentrically pivoted on said jaw base opposite said fixed jaw; said tubular base having serrated teeth on the underside of its upper wall at opposite sides of the upper slot therein; a post on said second base extending upwardly through the upper slot in the tubular base; a knob axially slidable on the upper end of the post and extending through the said upper slot and having a toothed head thereon below the slot provided with teeth adapted to engage those of the tubular base; means for normally yieldably raising the knob to engage the teeth of the base with those of the toothed head; and means for locking the knob in depressed position to maintain said teeth disengaged, permitting the spring to slam the movable jaw when retracted towards the fixed jaw to clamp an article therebetween.

Description of invention This invention relates to pipe wrenches or the like, and the principal object of the invention is to provide a self-adjusting positive-acting Wrench which may be used for rotating any cylindrical shape, same being designed to handle pipes ranging in size from approximately A1" to 6, and thus can be used with a range of the pipe sizes that is wider than normal, thus allowing the wrench to be applicable for competition with standard pipe wrenches as well as for Competition with pipe tongs such as ordinarily used in the oil industry; also by a simple changing of the set of jaw faces my pipe wrench may be loosen or fasten various sizes of bolts and nuts.

More specifically the primary object of the invention is to provide a pipe wrench comprising a tubular base having slots in its upper and lower walls intermediate its ends; a fixed jaw head mounted at the front end of the base having a lateral extension; 21 laterally disposed fixed jaw mounted on said extension; a block mounted in the rear end of the tube having an axial bore therein; a plunger slidable in said bore; a second head on the inner end of the plunger slidable within said tube; means for normally projecting said second head forwardly of the tube; a movable jaw base carried by the second head and having a neck slidable in the slot in the lower face of the tubular base; a movable jaw eccentrically pivoted on said movable jaw base opposite said fixed jaw; said tubular base having serrated teeth on the underside of its upper wall at opposite sides of the slot therein; a post on said movable jaw base extending upwardly through the slot in the upper face of the tubular base; a knob axially slidable on the upper end of the post and extending used to through the said upper'slot and having a toothed head 3,357,286 Patented Dec. 12, 1967 thereon below the slot provided with teeth adapted to engage those of the tubular base; means for normally yieldably raising the knob to engage the teeth of the base with those of the toothed head; and means for locking the knob in depressed position to maintain said teeth disengaged, permitting the spring to slam the movable jaw when retracted towards the fixed jaw to clamp an article therebetween.

Another object of the invention is to provide a wrench of the above type in which the lower end of the movable jaw base is bifurcated; a pivot pin housed in said bifurcations offset forwardly of the axis of the post, and said movable jaw being rockably mounted on said pin and having a serrated convex front face whose axis of curvature is offset from the pin; and said movable jaw having a heel at its rear end normally separated from the lower rear end of the movable jaw base, thereby permitting the jaw to rock when engaged with an article clamped between the fixed and movable jaws.

A further object of the invention is to provide a wrench of the above type in which said heel of the movable jaw engages the lower rear end of the movable jaw base only when the jaws engage said article and a clockwise rotative force is applied to the tube.

Other minor objects of the invention will be hereinafter set forth.

i will explain the invention with reference to the accompanying drawings, which illustrate several practical embodiments thereof, to enable others familiar with the art to adopt and use the same; and will summarize in the claims the novel features of construction, and novel combinations of parts, for which protection is desired.

In said drawings:

FIG. 1 is a side elevation of the wrench, partly in section, showing the movable jaw retracted.

FIG. 2 is a transverse section on the line 2-2, FIG. 1.

FIG. 3 is a top plan view of the wrench.

FIG. 4 is a side elevational view thereof.

FIG. 5 is a longitudinal section through the wrench on the line 5-5, FIG. 3, showing the movable jaw in operative position.

FIG. 6 is a transverse sectional view on the line 6-6, FIG. 5.

FIG. 7 is a transverse section on the line 7-7, FIG. 5.

FIG. 8 is a transverse section on the line 88, FIG. 5.

FIG. 9 is a transverse section on the line 99, FIG. 1.

FIG. 10 is a section on the line 1t 1tl, FIG. 1.

FIG. 11 is a plan view of a set of modified jaws for use with nuts and bolts.

As shown, my novel wrench preferably comprises a tubular base 1 of square or rectangular cross-section having at its rear end external threads or serrations 1a whereby a plastic or other handle extension 2, shown in dot-and-dash lines in FIG. 1, may be secured therearound to form a continuation of the tube 1.

The opposite or front end of the tube d has an internally tapped bore 1b extending to an internal annular shoulder 1c for the reception of a fixed jaw head 3 having a threaded extension 3b engaging the threads 1b of tube 1, the outer end of head 3 extending laterally of the axis of tube '1, as indicated at 3c having in its outer end a T-slot 3d (FIG. 6) receiving a correspondingly shaped lug 4:: (FIG. 6) on a fixed jaw member 4 of the wrench, the lug 4a being normally maintained against axial movement in slot 3d by a pin 412 (FIG. 6) whereby the fixed jaw 4 for-ms an extension of the lateral portion 3c of the head 3. The inner face of the fixed jaw 4-, as shown in FIGS. 1, 4 and 5, is provided with an elliptical recess 40, the walls of which are preferably serrated as shown, in order to grip one side of the pipe, tube, bolt or'the like engaged by the Wrench as shown in FIG. 5.

In the top wall of the tube 1 extending from a point adjacent to the serrated portion 1a thereof to a point adjacent the shoulder 1c is an axial slot 1d, as shown in FIG. 1, while a similar slot 1e is provided in the bottom wall of the tube '1, embracing substantially the same extent of the length of the tube 1. At the inner end of the slot 1d is an enlarged threaded bore 1), FIGS. 1, 3 and 5, receiving a threaded plug 5 which is removable from the bore 1f to permit insertion and removal of the parts of the movable jaw, hereinafter described.

Within the rear end of the tube 1 is a rectangular block 6 (FIG. 8) of length extending from the rear end of the tube to a point below the removable plug 5, said block 6 having an axially disposed central bore 6a therein. As shown in FIG. 8, block 6 carries splines 6b on its upper and lower faces engaging grooves in the faces of the upper and lower walls of the rectangular bore of tube 1, block 6 being maintained in fixed position in the tube 1 by means of set screws 7 or the like (FIG. 8) tapped through the wall of the tube 1 and into the block 6.

Slidably mounted in the bore 6a of block 6 is 2. cylindrical plunger 8 carrying a head 9 of square shape on its outer end, head 9 being preferably secured to the plunger 8 by the threaded engagement of an axial extension 8a in a tapped bore in the head 9, as shown in FIGS. 1 and 5, the head 9 being slidable axially of the bore of the tube 1 as the plunger 8 is actuated. Plunger 8 is normally yieldably projected forwardly of the tube 1 by means of a coiled spring 10 (FIGS. 1, 5 and 7) therearound having one end engaging the inner end of block 6 and its other end seated in a spring-centering recess 9x in the adjacent face of the head 9, the head 9 carrying the base 11 of the movable jaw, hereinafter described.

Extending forwardly and downwardly from the front face of the head 9, as shown in FIGS. 1, 2 and 5, are triangular side plates 91: which slope downwardly from the top of the head 9 adjacent each side wall of the tube 1 to a point forwardly of the head 9, the lower edges of the side plates 912 being inturned as at 90, as shown in FIGS. 2 and 10 to engage correspondingly shaped slots in the sides of the base 11 (FIG. 2), which carries the movable jaw member, hereinafter described, the inturned flanges 9c of the side walls 91) of head 9 preferably making a clip-lock into the corresponding slots 90 in the side base 11, as shown in FIG. 10, whereby the base 11 and the head 9 will substantially form a rigid unit, while the base 11 is in fact separable from the head 9.

As shown in FIGS. 1, 2 and 5, the top of base 11 extends above the bottom of the tube 1 and carries thereon an upstanding post 11a which extends upwardly through the slot 1d and terminates somewhat above the top wall of the tube 1. As shown in FIG. 2, the base 11 has a reduced neck 11b slidably fitting the slot 1e, and below the slot 1e the lower end of the base 11 is bifurcated as at 110 (FIG. 2) adjacent its front face receiving a pin 12 offset forwardly from the axis of the post 11a, pin 12 rotatably supporting the movable jaw 13, which is disposed opposite the fixed jaw 4 eccentrically of the axis of curvature of the front convex face of the jaw 13.

As shown, the front face of the movable jaw 13 is convex and provided with serrations 13a adapted to engage the side of a pipe P (FIG. 5) opposite from the fixed jaw 4. The movable jaw 13 is substantially triangular in shape and normally a slight angular gap X (FIG. 1) would exist between the lower rear end of the base 11 in rear of the pivot pin 12 and the heel 13b of the movable jaw, for the purpose hereinafter described, thereby permitting the movable jaw to rock slightly on the pin 12 when engaged with the pipe P.

Axially movably mounted upon the post 11a is a jaw locking-and-releasing knob 14 having a bore extending upwardly from its bottom slidably engaging the post 11a, said knob 14 having a knurled head 14a at its upper end disposed above the top of the tube 1, and having at its 4 lower end a tooth-carrying head 15 disposed within the bore of the tube 1, the main body portion of the knob 14 between the heads 14a and 15 being disposed in the slot 1d. as shown in FIGS. 1. 2 and 5.

In the upper face of the head 15 within the bore of tube 1 are replaceable teeth 16 (FIG. 5) adapted to engage serrations or teeth 1h (FIG. 5) formed on the undersurface of the top wall of the tube 1 at opposite sides of the slot 1d to lock the movable jaw 13 in adjusted position, a spring 17 around the post 11a disposed between the underside of the head 15 and the top of base 11 normally maintaining the teeth 16 of head 15 in engagement with the teeth 1/1 of the tube 1. Means are provided for disengaging the teeth 16 of the head 15 from the teeth 1h of the tube, the same comprising a transverse pin 11b on the post 11a adjacent its upper end, the ends of which pin normally slide in slots 140 (FIG. 1) in the bore of the knob 14, the upper ends of the slots 14c having bayonet portions whereby when the knob 14 is rotated into one position pin 11b will be disengaged from the bayonet slots and the spring 17 will raise the member 15 to engage the teeth 16 with the teeth 1h. However, when the knob 14 is depressed on the post 11a and rotated through a angle the spring 17 and head 15 will be depressed as shown in FIG. 1 and the teeth 16 of head 15 will be disengaged from the teeth 1k, and the teeth will remain so disengaged until the knob 14 is again rotated in the opposite direction through a 90 angle, after which the teeth 16 will reengage the teeth 1h, as shown in FIG. 5.

Instead of using the set of jaws 4 and 13 for engaging pipes P, the wrench may be readily adapted for engagement with non-cylindrical objects such as nuts and bolts or the like by replacing the fixed jaw 4 with a modified fixed jaw 18 shown in FIG. 11, which is identical in construction with the fixed jaw 4, except that the bolt or nut engaging face has a shallow V-shaped recess 18a (FIG. 11) formed therein; and the jaw 13 replaced by the jaw 19 shown in FIG. ll, which jaw has a heel 19a conforming with the heel 13b of FIG. 1, but instead of the convex serrated face 13a the work-engaging face is replaced by a half hexagonal recess 1% (FIG. 11), the faces 19b and 18a cooperating to readily engage a nut, bolt or the like.

In operation, in order to engage the wrench shown in the drawings with a pipe or bolt or nut, the wrench is picked up by the handle 1 or 2 and the knob 14a is manually depressed until the lock pin 11!; reaches the maximum height of the channels in the knob 14, thereby depressing the spring 17 and head 15 and disengaging the teeth 16 of the head 15 with the teeth 1k in the bore of the tube 1. The knob 14 while depressed is then rotated 90 clockwise until the ends of the pin 11b engage the bayonet slots at the tops of the slots 140 to lock and retain the knob 14 in depressed position in which the teeth 16 are disengaged from the teeth 1!: until the knob is subsequently released by reverse rotation. The knob 14 is then grasped by the index finger of the operator and pulled rearwardly, and while so holding the knob 14 the fixed jaw 4 (or 18) of the wrench is placed over the pipe P and the wrench pulled back firmly in a hooking manner. The knob 14 is then released allowing the spring 10 to slam the head 9 and base 11 forwardly, jamming the movable jaw 13 (or 19) against the pipe P (or nut) the force of spring 10 advancing the movable jaw 13 or 19 against the pipe P or nut firmly resulting in a positive action between the jaws 4 and 13 and the pipe P, so that no slippage may occur. Then the knob 14 is rotated in the opposite (counterclockwise) direction to disengage the locking pin 11b from the bayonet slots 14c permitting spring 17 to jam head 15 upwardly and thus engage the teeth 16 carried by the head 15 with the teeth 111 provided in the tube 1.

At this time it may be noticed that perhaps the teeth 16 of base 15 do not engage perfectly with the teeth 1h of the tube 1, this being caused by several contributing factors:

1) The relationship of a particular diameter pipe P to the advance of the movable jaw 13, and the elliptical shape of the jaw 4 will partially cause the trouble since the jaws are to come in sets to handle different ranges of pipe diameters;

(2) Tolerance between related parts:

(a) Necessary tolerance between base 11 and the track provided for it in the body of the tube 1;

(b) The heel 13b (or 19a) of movable jaw 13 (or 19) and the lower rear end of the base 11 are to come in contact only when the jaws are engaged, and likewise when a clockwise or upward force on the wrench has been applied. When a counterclockwise or downward force is applied the heel 13b of jaw 13 and the rear end of the base 11 will separate and the eccentric jaw 13 will continue to advance as such. Thus, in event that the teeth 16 of base 15 have not properly engaged with the teeth 1h of the tube l, a continuous downward pull on the wrench will force base 11 allowing teeth 16 to engage completely with teeth 1h. As long as the wrench is pulled downwardly (counterclockwise) the eccentric jaw 13 will continue to advance, and when it is worked in the fashion of a ratchet, the jaw 13 will continuously release upon upward force. However, if the force has been too great it may jam the eccentric jaw 13, but there is no problem, since by depressing the knob 14a on post 11a and continuing to advance the wrench jaw will cause the assembly 11-13 to be forced rearwardly. When the work is finished the knob 14a will be depressed and moved rearwardly clearing the pipe P.

I do not limit my invention to the exact forms shown in the drawings, for obviously changes may be made therein within the scope of the claims.

I claim:

1. A pipe wrench comprising a tubular base having slots in its upper and lower walls intermediate its ends; a fixed jaw head mounted at the front end of the base having a lateral extension; a laterally disposed fixed jaw mounted on said extension; a block mounted in the rear end of the tube having an axial bore therein; a plunger slidable in said bore; a second head on the inner end of the plunger slidable within said tube; means for normally projecting said second head forwardly of the tube; a movable jaw base carried by the second head and having a neck slidable in the slot in the lower face of the tubular base; a movable jaw eccentrically pivoted on said movable jaw base opposite said fixed jaw; said tubular base having serrated teeth on the underside of its upper wall at opposite sides of the slot therein; a post on said movable jaw base extending upwardly through the slot in the upper face of the tubular base; a knob axially slidabie on the upper end of the post and extending through the said upper slot and having a toothed head thereon below the slot provided with teeth adapted to engage those of the tubular base; means for normally yieldably raising the knob to engage the teeth of the base with those of the toothed head; means for locking the knob in depressed position to maintain said teeth disengaged, permitting the spring to slam the movable jaw when retracted towards the fixed jaw to clamp an article therebetween; said means for raising the knob comprising a spring around the post interposed between the top of the movable jaw base and the underside of the toothed head.

2. A pipe wrench comprising a tubular base having slots in its upper and lower walls intermediate its ends; a fixed jaw head mounted at the front end of the base having a lateral extension; a laterally disposed fixed jaw mounted on said extension; a block mounted in the rear end of the tube having an axial bore therein; a plunger slidable in said bore; a second head on the inner end of the plunger slidable within said tube; means for normally projecting said second head forwardly of the tube; a movable jaw base carried by the second head and having a neck slidable in the slot in the lower face of the tubular base; a movable jaw eccentrically pivoted on said movable jaw base opposite said fixed jaw; said tubular base having serrated teeth on the underside of its upper wall at opposite sides of the slot therein; a post on said movable jaw base extending upwardly through the slot in the upper face of the tubular base; a knob axially slidable on the upper end of the post and extending through the said upper slot and having a toothed head thereon below the slot provided with teeth adapted to engage those of the tubular base; means for normally yieldably raising the knob to engage the teeth of the base with those of the toothed head; means for locking the knob in depressed position to maintain said teeth disengaged, permitting the spring to slam the movable jaw when retracted towards the fixed jaw to clamp an article therebetween; said locking means comprising a pin transfixing the post above the toothed head having its ends engaging opposed slots in the bore of the knob, and the upper ends of said slots having lateral bayonet portions, whereby when the knob is depressed and rotated on said post the ends of the pin will engage the bayonet portions and retain the knob depressed.

3. A pipe wrench comprising a tubular base having slots in its upper and lower walls intermediate its ends; a fixed jaw head mounted at the front end of the base having a lateral extension; a laterally disposed fixed jaw mounted on said extension; a block mounted in the rear end of the tube having an axial bore therein; a plunger slidable in said bore; a secondihead on the inner end of the plunger slidable within said tube; means for normally projecting said second head forwardly of the tube; a movable jaw base carried by the second head and having a neck slidable in the slot in the lower face of the tubular base; a movable jaw eccentrically pivoted on said movable jaw base opposite said fixed jaw; said tubular base having serrated teeth on the underside of its upper wall at opposite sides of the slot therein; a post on said movable jaw base extending upwardly through the slot in the upper face of the tubular base; a knob axially slidable on the upper end of the post and extending through the said upper slot and having a toothed head thereon below the slot provided with teeth adapted to engage those of the tubular base; means for normally yieldably raising the knob to engage the teeth of the base with those of the toothed head; means for locking the knob in depressed position to maintain said teeth disengaged, permitting the spring to slam the movable jaw when retracted towards the fixed jaw to clamp an article therebetween; said second head having side plates extending downwardly and forwardly of its front face adjacent opposite sides of the bore of the tubular base, the lower edges of the side plates being inturned and engaging slots in the sides of the movable jaw base.

4. In a wrench as set forth in claim 3, said inturned edges making a clip-lock into said slots in the movable jaw base to form a rigid but separable unit.

5. A pipe wrench comprising a tubular base having slots in its upper and lower walls intermediate its ends; a fixed jaw head mounted at the front end of the base having a lateral extension; a laterally disposed fixed jaw mounted on said extension; a block mounted in the rear end of the tube having an axial bore therein; a plunger slidable in said bore; a second head on the inner end of the plunger slidable within said tube; means for normally projecting said second head forwardly of the tube; a movable jaw base carried by the second head and having a neck slidable in the slot in the lower face of the tubular base; a movable jaw eccentrically pivoted on said movable jaw base opposite said fixed jaw; said tubular base having serrated teeth on the underside of its upper wall at opposite sides of the slot therein; a post on said movable jaw base extending upwardly through the slot in the upper face of the tubular base; a knob axially slidable on the upper end of the post and extending through the said upper slot and having a toothed head thereon below the slot provided with teeth adapted to engage those of the tubular base; means for normally yieldably raising the knob to engage the teeth of the base with those of the toothed head; means for locking the knob in depressed position to maintain said teeth disengaged, permitting the spring to slam the movable jaw when retracted towards the fixed jaw to clamp an article therebetween; the lower end of the movable jaw base being bifurcated; a pivot pin housed in said bifurcations offset forwardly of the axis of the post, and said movable jaw being rockably mounted on said pin and having a serrated convex front face whose axis of curvature is offset from the pin; and said movable jaw having a heel at its rear end normally separated from the lower rear end of the movable jaw base, thereby permitting the jaw to rock when engaged with an article clamped between the fixed and movable jaws.

6. In a wrench as set forth in claim 5, said heel of the movable jaw engaging the lower rear end of the movable jaw base only when the jaws engage said article and a clockwise rotative force is applied to the tube.

7. A pipe wrench comprising a tubular base' of rectangular cross-section having slots in its upper and lower walls extending intermediate its ends; a fixed jaw head mounted at the front end of the base having a lateral extension; a fixed jaw removably mounted on said extension; a rectangular block mounted in the rear end of the tube having an axial bore therein; a plunger slidable in said bore; a second head on the inner end of the plunger slidable within said tube; a coiled spring around said plunger interposed between said block and second head for normallly projecting said second head forwardly of the tube; a movable jaw base carried by the second head and having a reduced neck slidable in the slot in the lower face of the tubular base; a movable jaw eccentrically pivoted on said movable jaw base opposite said fixed jaw; said tubular base having serrated teeth on the underside of its upper wall at opposite sides of the slot therein; a post on said movable jaw base extending upwardly through the slot in the upper face of the tubular base; a knob axially slidable on the upper end of the post and extending through the said upper slot and having a toothed head thereon below the slot provided with teeth adapted to engage those of the tubular base; means for normally yieldably raising the knob to engage the teeth of the base with those of the toothed head; and means for locking the knob in depressed position to maintain said teeth disengaged, permitting the spring to slam the movable jaw when retracted towards the fixed jaw to clamp an article therebetween.

8. In a wrench as set forth in claim 7, said means for raising the knob comprising a second coiled spring around the post interposed between the top of the movable jaw base and the underside of the toothed head.

9. In a wrench as set forth in claim 7, said locking means comprising a pin transfixing the post above the toothed head having its ends engaging opposed slots in the bore of the knob, and the upper ends of said slots having lateral bayonet portions, whereby when the knob is depressed and rotated on said post the ends of the pin will engage the bayonet portions and retain the knob depressed.

10. In a wrench as set forth in claim 7, said second head having triangular side plates extending downwardly and forwardly of its front face adjacent opposite sides of the bore of the tubular base, the lower edges of the side plates being inturned and engaging slots in the sides of the movable jaw base.

11. In a wrench as set forth in claim 10, said inturned edges making a clip-lock into said slots in the movable jaw base to form a rigid but separable unit.

12. In a wrench as set forth in claim 7, the lower end of the movable jaw base being bifurcated; a pivot pin housed in said bifurcations offset forwardly of the axis of the post, and said movable jaw being rockably mounted on said pin and having a serrated convex front face whose axis of curvature is offset from the pin; and said movable jaw having a heel at its rear end normally separated from the lower rear end of the movable jaw base, thereby permitting the jaw to rock when engaged with an article clamped between the fixed and movable aws.

13. In a wrench as set forth in claim 12, said heel of the movable jaw engaging the lower rear end of. the movable jaw base only when the jaws engage said article and a clockwise rotative force is applied to the tube.

References Cited UNITED STATES PATENTS 597,611 1/1898 Haye et al. 1,061,046 5/1913 Carp 81145 1,502,892 7/1924 Walz Sl 1,512,723 10/1924 Tabert 81-145 X 1,593,337 7/1926 Johnson et a1 81145 MILTON S. MEHR, Primary Examiner, 

1. A PIPE WRECH COMPRISING A TUBULAR BASE HAVING SLOTS IN ITS UPPER AND LOWER WALLS INTERMEDIATE ITS ENDS; A FIXED JAW HEAD MOUNTED AT THE FRONT END OF THE BASE HAVING A LATERAL EXTENSION; A LATERALLY DISPOSED FIXED JAW MOUNTED ON SAID EXTENSION; A BLOCK MOUNTED IN THE REAR END OF THE TUBE HAVING AN AXIAL BORE THEREIN; A PLUNGER SLIDABLE IN SAID BORE; A SECOND HEAD ON THE INNER END OF THE PLUNGER SLIDABLE WITHIN SAID TUBE; MEANS FOR NORMALLY PROJECTING SAID SECOND HEAD FORWARDLY OF THE TUBE; A MOVABLE JAW BASE CARRIED BY THE SECOND HEAD AND HAVING A NECK SLIDABLE IN THE SLOT IN THE LOWER FCE OF THE TUBULAR BASE; A MOVABLE JAW ECCENTRICALLY PIVOTED ON SAID MOVABLE JAW BASE OPPOSITE SAID FIXED JAW; SAID TUBULAR BASE HAVING SERRATED TEETH ON THE UNDERSIDE OF ITS UPPER WALL AT OPPOSITE SIDES OF THE SLOT THEREIN; A POST ON SAID MOVABLE JAW BASE EXTENDING UPWARDLY THOROUGH THE SLOT IN THE UPPER FACE OF THE TUBULAR BASE; A KNOB AXIALLY SLID- 